A radio access network (RAN) is a network between mobile devices and a core network. In the RAN, digital baseband (BB) processing is typically performed at wireless base stations located at remote cell sites. However, in a cloud RAN (C-RAN), digital baseband (BB) processing is relocated to centralized baseband units (BBUs) located at a central site near a core network and remote radio units (RRUs) replace the wireless base stations. The RRUs interface with antennas for wireless radio frequency (RF) transmission and reception. The RRUs require limited digital BB processing.
In the C-RAN, a fronthaul connects the BBUs to the RRUs. The fronthaul digitizes wireless channels, aggregates the digitized channels, and transports the aggregated channels using an aggregated fiber optical channel or aggregated microwave channel. Because the aggregated channel has a high data rate, it requires complex communications systems. An efficient mobile fronthaul (EMF), or aggregated touchless fronthaul, provides a digital signal processing (DSP)-based channel aggregation and de-aggregation scheme with low latency, high bandwidth efficiency, and high throughput.